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Obstacle

About: Obstacle is a research topic. Over the lifetime, 9517 publications have been published within this topic receiving 94760 citations. The topic is also known as: impediment & barrier.


Papers
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Journal ArticleDOI
TL;DR: The artificial potential field method combined with rotational vectors for a general problem of multi-unmanned aerial vehicle (UAV) systems tracking a moving target in dynamic three-dimensional environment is considered.
Abstract: This paper considers the artificial potential field method combined with rotational vectors for a general problem of multi-unmanned aerial vehicle (UAV) systems tracking a moving target in dynamic three-dimensional environment. An attractive potential field is generated between the leader and the target. It drives the leader to track the target based on the relative position of them. The other UAVs in the formation are controlled to follow the leader by the attractive control force. The repulsive force affects among the UAVs to avoid collisions and distribute the UAVs evenly on the spherical surface whose center is the leader-UAV. Specific orders or positions of the UAVs are not required. The trajectories of avoidance obstacle can be obtained through two kinds of potential field with rotation vectors. Every UAV can choose the optimal trajectory to avoid the obstacle and reconfigure the formation after passing the obstacle. Simulations study on UAV are presented to demonstrate the effectiveness of proposed method.

25 citations

Journal ArticleDOI
Eun Yi Kim1
28 Oct 2016-Sensors
TL;DR: From the experiments that were performed in various environments, it can be proved that the proposed intelligent wheelchair system can recognize different types of outdoor places with 98.3% accuracy and produce paths that avoid obstacles with 92.0% accuracy.
Abstract: An intelligent wheelchair (IW) system is developed in order to support safe mobility for disabled or elderly people with various impairments The proposed IW offers two main functions: obstacle detection and avoidance, and situation recognition First, through a combination of a vision sensor and eight ultrasonic ones, it detects diverse obstacles and produces occupancy grid maps (OGMs) that describe environmental information, including the positions and sizes of obstacles, which is then given to the learning-based algorithm By learning the common patterns among OGMs assigned to the same directions, the IW can automatically find paths to prevent collisions with obstacles Second, it distinguishes a situation whereby the user is standing on a sidewalk, traffic intersection, or roadway through analyzing the texture and shape of the images, which aids in preventing any accidents that would result in fatal injuries to the user, such as collisions with vehicles From the experiments that were performed in various environments, we can prove the following: (1) the proposed system can recognize different types of outdoor places with 983% accuracy; and (2) it can produce paths that avoid obstacles with 920% accuracy

25 citations

Proceedings ArticleDOI
26 May 2015
TL;DR: A novel, decentralized, control-theoretic approach to address collision avoidance for multi-robot systems by creating a virtual obstacle at the mean position of the robots such that each robot will avoid the closest obstacle when a collision is possible.
Abstract: This paper presents a novel, decentralized, control-theoretic approach to address collision avoidance for multi-robot systems. We create a virtual obstacle at the mean position of the robots. A control is be designed such that each robot will avoid the closest obstacle when a collision is possible. The closest obstacle can be the virtual obstacle or the nearest robot. We present two such control laws. The first assumes perfect knowledge of the velocities of all nearby robots and can allow a saturated velocity input for each robot. In practice, the velocities of the other robots are hard to measure or estimate precisely. Therefore, the second control law removes the assumption of known velocities based on a high-gain, robust control scheme. We prove the first control scheme is globally asymptotically stable, and the robust control law is globally uniformly ultimately bounded. To verify the effectiveness of the proposed approach, Monte Carlo simulations and experiments have been conducted.

25 citations

Proceedings ArticleDOI
13 Apr 2011
TL;DR: In this article, the authors describe a routing strategy for obstacle avoidance using an omni-directional camera based obstacle detection, using a panoramic vision system and a sailboat simulation results.
Abstract: Unmanned autonomous vehicles have the potential to operate for extended periods of time in different environments like in the air or the sea. These environments are often complex and arise many challenges for the unmanned vehicles research. The ASAROME project1 (Autonomous Sailing Robot for Oceanographic Measurements) is focused on an autonomous sailboat to make measurements and observations in the marine environment for long term. This paper describes a routing strategy for obstacle avoidance using an omni-directional camera based obstacle detection. Experiments with a panoramic vision system and sailboat simulation results have shown the expected performances for obstacle detection and avoidance.

25 citations

Proceedings ArticleDOI
23 May 2015
TL;DR: In this paper, a leader-follower formation control of multi-robot was studied, and the obstacle avoidance could be achieved by Artificial Potential Field method, and robots can pass the area of obstacle smoothly.
Abstract: Leader-Follower formation control of multi-robot was studied in this paper. A formation and obstacle avoidance method with multi-robot based on the combination of Closed-loop control and Artificial Potential Field was presented. According to the position information of leader, Closed-loop control was introduced to realize the tracking of the follower to the leader, and the formation control was achieved. The obstacle avoidance could be achieved by Artificial Potential Field method, and the robots can pass the area of obstacle smoothly. The simulation result shows that the proposed method can achieve the expected control effect, and it can solve this kind of problems effectively.

25 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
20231,483
20223,389
2021407
2020817
2019873